Kerry: "Hard to imagine how Assad can govern Syria in future, but it's not an issue to be decided on now."

U.S. Secretary of State John Kerry says he can hardly imagine how Syrian President Bashar al-Assad can remain in power in the future, although he believes this is not an issue to be decided on right now.

"It's impossible for me as an individual to understand how Syria could possibly be governed in the future by the man who has committed the things that we know have taken place. But that's not - I'm not going to decide that tonight. And I'm not going to decide that in the end. Because the Geneva communique says that the transitional government has to be chosen by mutual consent by the parties," Kerry said at a press conference following negotiations with Russian Foreign Minister Sergei Lavrov in Moscow late on Tuesday.

"Who are the parties? The parties are the current regime and the opposition. So what we're going to undertake to do is to try to get them in a position where they, representing the people they represent - Syria and the interests they represent - put people into a transitional government by mutual consent," he added.

"Up until now, I think there has been a perception that Russia and the United States haven't been particularly on the same page of cooperating in this effort. So what I think is significant is that we are here to say that we are going to cooperate in trying to implement the Geneva communique, and I think our understanding of that communique is very similar," he said.